This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this research is to compare the safety and efficacy and tolerability of different combinations of anti-HIV drugs. All the anti-HIV drugs that are being used in this study are approved by the U.S. Food and Drug Administration (FDA) for treating HIV. The following drug combinations will be used in this study: [unreadable]?[unreadable]Efavirenz (EFV) with emtricitabine (FTC) and tenofovir (TDF) [unreadable]?[unreadable]EFV with abacavir (ABC) and lamivudine (3TC) [unreadable]?[unreadable]Atazanavir (ATV) with ritonavir (RTV) and FTC/TDF [unreadable]?[unreadable]ATV with RTV and ABC/3TC